The present invention relates to a playback apparatus for magnetic tape recording information, and more particularly, to a playback apparatus for playing back or reproducing a recorded image signal of a magnetic tape where image signals are recorded on tracks inclined with respect to a longitudinal direction of a magnetic tape in the manner that tracks having the same azimuth angle are formed every other track.
Hitherto, there have been proposed Video Tape Recorders (VTR) of the inclined azimuth recording system (helical scan type) where image signals are recorded on tracks inclined (inclined tracks) with respect to a longitudinal direction of a magnetic tape wound around the circumference of a rotary drum over a predetermined angular range with the magnetic tape being in contact therewith by means of a pair of rotary heads having azimuth angles different from each other affixed or mounted on the rotary drum in the manner that tracks having the same azimuth angle are formed every other track, and that each track is allowed to serve as a signal recording area corresponding to one field.
In such a VTR, as shown in FIG. 1, a pair of rotary heads R.sub.A and L.sub.B having azimuth angles different from each other, are arranged and affixed on a rotary drum 1 in the manner that they are positioned opposite to each other with an angular distance of 180 degrees therebetween. Reference symbols A and B represent the symbols of azimuth, respectively, and show that the azimuth angles of oppsite heads are different from each other.
As shown in FIG. 2, the above-mentioned inclined tracks 1A, 1B, 2A, 2B, 3A, 3B, and the like are formed on a magnetic tape 2 recorded by the above-described VTR in the manner that tracks having the same azimuth angle described above are in line.
In FIG. 2, numbers 1, 2 and 3 and reference symbols A and B attached to the tracks represent frame numbers and symbols of azimuth, respectively.
The operation in the special playback, e.g., still picture playback or slow motion playback etc. of the image signals recorded on a magnetic tape in the manner that tracks having the same azimuth angle are formed every other track inclined with respect to the longitudinal direction of the magnetic tape in the manner stated above, will now be described.
Generally, when frame playback is conducted by the still picture playback of an object moving at a high-speed, an image vibration might take place due to time differences between fields. For this reason, field playback is carried out in the case of the special playback. Heads having the same azimuth angle are required in order to conduct the field playback. However, since inclined tracks having the same azimuth angle are positioned every other track as described above, and the number of tracks which can be played back by this head is reduced to one half of the entire number of tracks.